One of the most effective forms of resistance that slaves employed against their masters was?

Enslaved African Americans resisted slavery in a variety of active and passive ways. "Day-to-day resistance" was the most common form of opposition to slavery. [ Breaking tools, feigning illness, staging slowdowns, and committing acts of arson and sabotage- all were forms of resistance and expression of slaves' alienation from their masters.
Running away was another form of resistance. Most

slaves ran away relatively short distances and were not trying to permanently escape from slavery. ]

Weegy: By the middle of the seventeenth century, the full impact of the
Commercial Revolution had not yet been experienced in Europe. [ Neither the
Portuguese nor the Spanish, who were dominant overseas until the late 1500s,
could maintain their initial advantages over the long term. Portugal lacked
manpower and resources required by an empire spread over three continents.
Spain wasted the wealth of the New World in continuous wars, while neglecting
to develop its own economy. Yet the fabulous "Iberian Age" brought a momentous
transition, as Lisbon and Seville received the world's wealth in gold, silver,
slaves, and spices. In 1503 Portuguese pepper cost 80 percent less than that
which came through Venice and the eastern Mediterranean. ^1 During the
sixteenth century, Spanish bullion, flowing into northern banks and markets,
provided a major stimulus to European capitalism and prepared the way for
empire-building by the Dutch, English, and French after 1600. Iberian
expansion also inspired other Europeans with hope and confidence while
effecting a mixing of peoples, a diffusion of cultures, and an
intercontinental exchange of plants and animals such as the world had never
seen before. ] (More)